Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate read-only, idempotent, and open-world behavior. The description adds valuable behavioral details: analyzes audio fingerprint against 80M+ tracks, returns artist/title/album/release date plus Spotify/Apple Music links, and accepts various audio formats (MP3, WAV, OGG, etc.). This goes beyond annotations without contradiction.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is exceptionally concise: two sentences that front-load the core purpose (first sentence) and add key details (fingerprint, output fields, supported formats) in the second. Every sentence earns its place with no redundancy or filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's low complexity (single parameter), rich annotations, and existence of an output schema, the description covers all essential aspects: what it does, how it works (fingerprinting), what it returns, and input constraints. It is fully adequate for an agent to correctly invoke the tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The single 'url' parameter is fully described in the input schema (type, format, example). The description reiterates accepted formats and mentions the API's analysis capability, but adds minimal new semantic value beyond what the schema already provides. Baseline 3 is appropriate due to high schema coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: 'Identify a song from an audio file URL — like Shazam for AI agents.' It specifies the verb (identify), resource (song from audio), and differentiates it from sibling music tools like music.artists.search or music.audd.lyrics by focusing on audio fingerprinting.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage when you have an audio URL to identify, but does not explicitly state when not to use it or mention alternative tools for related tasks (e.g., lyrics lookup, artist details). The analogy to Shazam provides some context but is insufficient for clear decision-making.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.